In a positive electrode of a non-aqueous electrolyte secondary battery represented by a lithium ion secondary battery, a lithium-containing composite oxide including nickel is used as a positive electrode active material.
The positive electrode is produced as follows. A positive electrode active material, a binder, and a conductive agent are mixed in the presence of a prescribed dispersing medium to prepare a positive electrode slurry. The positive electrode slurry is applied onto a positive electrode core material made of an aluminum foil etc., which is then dried to form a positive electrode material mixture layer, thereby obtaining a positive electrode precursor. Subsequently, the positive electrode precursor is rolled with rollers. The positive electrode is produced in this manner.
Various studies have been made on the lithium-containing composite oxide including nickel. For example, with the aim of improving high-temperature characteristics, it has been proposed to coat a surface of lithium nickelate (LiNiO2) with lithium titanate (see Patent Literature 1).